The present invention relates to a hydraulic piston machine.
DE 10 2004 060 954 A1, for example, shows a dual wobble-plate machine, in which a plurality of pistons is accommodated in a stationary barrel, the pistons being guided in pairs in opposite directions in the barrel and bounding a common working chamber. The axial displacement of the opposing pistons takes place using two wobble plates which are situated on either side of the barrel and are non-rotatably connected to a drive shaft. Each piston bears via a sliding block having a through-bore against the wobble plate assigned to it. A capillary tube passes through the piston, via which the pressure medium is directed to the sliding surface of the sliding block, thereby supporting the sliding block in a hydrostatic manner. In this known solution, the pressure medium is supplied to the working chambers via a suction valve accommodated on each of the end sections of the pistons that face the working chambers, each suction valve bounding a pressure chamber which is connected via inclined bores formed in the piston foot to suction connections of the axial piston machine. Pressure valves which are situated radially or axially in the piston barrel are provided between the working chamber and a pressure connection in order to discharge the pressure medium.
The disadvantage of a piston machine of this type is that the inclined bores provided in the piston foot for supplying the pressure medium are only capable of allowing a limited volumetric flow to take place, and so filling problems may occur, at high rotational speeds in particular. A further disadvantage of this known solution is that a valve design of this type is extremely complicated due to the placement of the suction and pressure valves in the piston and/or in the working chamber between the piston, thereby requiring a complex housing design.